To evaluate the correlation between lens opacity degrees and phacoemulsification cumulated dissipated energy (CDE) values in patients with age-related cataract by applying 25-MHz panoramic ultrasound biomicroscopy (UBM).
This observational study was conducted in 227 patients (294 eyes) with age-related cataract. Patient ages ranged from 45 to 91 years. According to the lens images acquired by 25-MHz UBM, the objective indexes of lens opacity degrees were determined by using the ImageJ software. The correlation between lens opacity degrees (pixel units) and CDE values of phacoemulsification were mainly analyzed.
The means of measurements were as follows: preoperative LogMAR corrected distance visual acuity, anterior chamber depth, and central lens thickness was 1.10 ± 0.61, 2.52 ± 0.51, and 4.34 ± 0.60 mm, respectively. The mean 25-MHz UBM-measured lens opacity degree was 101.30 ± 19.70 pixel units, and the mean CDE value was 9.74 ± 9.10. There was a linear correlation between pixel units and the CDE value, as well as LogMAR corrected distance visual acuity ( r = 0.38 and 0.50, respectively; both P < 0.05). Age correlated with anterior chamber depth and lens thickness ( r = −0.18 and 0.16, respectively; both P < 0.05) but not with pixel units ( r = −0.08, P > 0.05).
The 25-MHz UBM has significant advantages in displaying the opacity feature of age-related cataract. The 25-MHz UBM combined with ImageJ software can be used to evaluate the opacity degree of age-related cataract quantitatively and may help predict the phacoemulsification parameters in cataract surgery.